1 /* 2 * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 #ifndef SHARE_GC_Z_ZMARKTERMINATE_INLINE_HPP 25 #define SHARE_GC_Z_ZMARKTERMINATE_INLINE_HPP 26 27 #include "runtime/atomic.hpp" 28 29 inline ZMarkTerminate::ZMarkTerminate() : 30 _nworkers(0), 31 _nworking_stage0(0), 32 _nworking_stage1(0) {} 33 34 inline bool ZMarkTerminate::enter_stage(volatile uint* nworking_stage) { 35 return Atomic::sub(nworking_stage, 1u) == 0; 36 } 37 38 inline void ZMarkTerminate::exit_stage(volatile uint* nworking_stage) { 39 Atomic::add(nworking_stage, 1u); 40 } 41 42 inline bool ZMarkTerminate::try_exit_stage(volatile uint* nworking_stage) { 43 uint nworking = Atomic::load(nworking_stage); 44 45 for (;;) { 46 if (nworking == 0) { 47 return false; 48 } 49 50 const uint new_nworking = nworking + 1; 51 const uint prev_nworking = Atomic::cmpxchg(nworking_stage, nworking, new_nworking); 52 if (prev_nworking == nworking) { 53 // Success 54 return true; 55 } 56 57 // Retry 58 nworking = prev_nworking; 59 } 60 } 61 62 inline void ZMarkTerminate::reset(uint nworkers) { 63 _nworkers = _nworking_stage0 = _nworking_stage1 = nworkers; 64 } 65 66 inline bool ZMarkTerminate::enter_stage0() { 67 return enter_stage(&_nworking_stage0); 68 } 69 70 inline void ZMarkTerminate::exit_stage0() { 71 exit_stage(&_nworking_stage0); 72 } 73 74 inline bool ZMarkTerminate::try_exit_stage0() { 75 return try_exit_stage(&_nworking_stage0); 76 } 77 78 inline bool ZMarkTerminate::enter_stage1() { 79 return enter_stage(&_nworking_stage1); 80 } 81 82 inline bool ZMarkTerminate::try_exit_stage1() { 83 return try_exit_stage(&_nworking_stage1); 84 } 85 86 #endif // SHARE_GC_Z_ZMARKTERMINATE_INLINE_HPP